SUMMARY This renewal proposal seeks continuing support for the T32 Molecular Biophysics Predoctoral Training Program at the University of Colorado, Boulder (CU), currently in its 14th year of NIH and CU support. The goal of the Biophysics Training Program is to prepare exceptional, highly motivated biophysics students for productive research careers. The 39 training faculty are an outstanding, internationally recognized group of investigators from 5 Ph.D.-granting units: Biochemistry, Chemical & Biological Engineering, Chemistry, Molecular, Cellular & Developmental Biology, and Physics. These faculty, together with their students, are using state-of-the-art biophysical methods to elucidate fundamental aspects of macromolecular structure, dynamics, mechanism, and function in biological systems ranging from single molecules to complex, multi-component assemblies to living cells. Many of these projects focus on questions of direct relevance to human health and disease. Biophysics is the most rapidly growing research field on the Boulder campus. Of the 39 current training faculty, 21 were hired since the program began, including 4 in the past year. The Biophysics Training Program has been a key driving force behind this growth. The training program, jointly supported by NIH and University funds, has established a thriving biophysical community with extensive collaborations among biophysicists in different laboratories and departments. Moreover, the program provides rigorous, innovative training for predoctoral students of biophysics, ensuring that such students receive the broad, interdisciplinary foundation needed to carry out cutting edge biophysical research. Required coursework includes biophysical courses developed specifically for the program and a Responsible Conduct of Research course. Training during the first year includes coursework, laboratory rotations, and teaching duties. Training during the second year includes additional coursework and defense of the planned thesis project in an oral PhD candidacy exam. Following the second year, students meet yearly with a faculty committee that provides independent feedback on their thesis research. In all training years, regular Biophysics Seminars, Supergroup meetings and career development activities yield additional training experiences and stimulate strong communication and collaboration between biophysical students, faculty, and laboratories. During the current funding period, the training program has exhibited strong progress in multiple dimensions as evidenced by 1) recruitment of growing numbers of high quality faculty and students, 2) increased participation by matriculates, 3) increased participation and graduation of underrepresented groups, 4) innovations in training, 5) strong publication, graduation, and postdoctoral and career placement rates of trainees, and 6) multiple collaborations between training laboratories.